Why we shouldn't panic about those coronavirus variants just yet

Variants don't trick many T cells, new study finds
Coronavirus particles
Posted at 4:50 PM, Jan 27, 2021
and last updated 2021-01-27 20:41:47-05

SAN DIEGO (KGTV) -- As scientists around the world race to study the newly emerging variations of SARS-CoV-2, researchers at the La Jolla Institute for Immunology say new computer models offer encouraging clues about the durability of our immunity to these mutations.

Moderna and Pfizer reported this week their vaccines remain effective against variants first spotted in the United Kingdom and South Africa, but both companies announced they are working on a booster shot in case a variant shows significant resistance.

A study out Monday suggests the South Africa variant may dodge some of the antibodies generated by the vaccines. Based on blood samples from eight people, neutralizing antibodies were 83 percent less effective against the South Africa variant, a six-fold reduction, Moderna reported.

Still, the antibodies “remain above levels that are expected to be protective” based on tests in monkeys, the company said.

Although fewer antibodies may recognize the mutant strain, there are other aspects of our immune system capable of lending a hand, said LJI Professor Dr. Alessandro Sette.

The journal Cell Reports Medicine published research from Dr. Sette’s team Wednesday showing that about 90 percent of the T cell response remained intact against the UK variant. The team, which was co-led by LJI Instructor Dr. Alba Grifoni, analyzed samples from 99 COVID survivors.

Ongoing computer modeling suggests a similar level of efficacy against the South Africa variant, Sette said. Roughly 90 percent of the T cells should be able to recognize features on that variant.

“It might not prevent the infection, but from what we know, it may actually make the disease a lot less severe,” he said.

Another reason for optimism: variants in different parts of the world share several of the same mutations. That suggests the virus may not have an infinite number of escape hatches at its disposal.

“It is quite possible that the virus already used all its tricks,” Sette said.

If the virus has exhausted its best evolutionary tricks, it means one vaccine booster shot might be all we need -- if we even need one at all.

Since mRNA vaccines are built using genetic code, they can be updated quickly. Pfizer’s German partner BioNTech said it could update its vaccine in six weeks, meaning it could be ready for public release in a matter of months.

Sette said it’s still not a forgone conclusion we’ll need it. “You buy insurance not planning to use it,” he said.